Police in western Pennsylvania have arrested a suspect in the stabbing death of his girlfriend's son over the weekend.

Forty-three-year-old Michael Monroe is charged with criminal homicide, terroristic threats and simple assault in Sunday's death of 22-year-old Dereck Frye.

Authorities allege in a criminal complaint that Monroe argued with his girlfriend after he came home early Sunday to their Fineview residence.

Police allege that he choked her, then left the bedroom but returned carrying a bloody butcher knife and threatened her. She said she fled but saw her son upstairs unresponsive, and he was pronounced dead at the scene Officers spotted Monroe's car later that afternoon and arrested him.

Court documents don't list an attorney for Monroe, who was being held in the Allegheny County jail overnight.